§ 761.71 High efficiency boilers.

(a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but <500 ppm:

(1) The boiler shall comply with the following criteria:

(i) The boiler is rated at a minimum of 50 million BTU hours.

(ii) If the boiler uses natural gas or oil as the primary fuel, the carbon monoxide concentration in the stack is ≤50 ppm and the excess oxygen is at least 3 percent when PCBs are being burned.

(iii) If the boiler uses coal as the primary fuel, the carbon monoxide concentration in the stack is ≤100 ppm and the excess oxygen is at least 3 percent when PCBs are being burned.

(iv) The mineral oil dielectric fluid does not comprise more than 10 percent (on a volume basis) of the total fuel feed rate.

(v) The mineral oil dielectric fluid is not fed into the boiler unless the boiler is operating at its normal operating temperature (this prohibits feeding these fluids during either start up or shut down operations).

(vi) The owner or operator of the boiler:

(A) Continuously monitors and records the carbon monoxide concentration and excess oxygen percentage in the stack gas while burning mineral oil dielectric fluid; or

(B) If the boiler will burn <30,000 gallons of mineral oil dielectric fluid per year, measures and records the carbon monoxide concentration and excess oxygen percentage in the stack gas at regular intervals of no longer than 60 minutes while burning mineral oil dielectric fluid.

(vii) The primary fuel feed rates, mineral oil dielectric fluid feed rates, and total quantities of both primary fuel and mineral oil dielectric fluid fed to the boiler are measured and recorded at regular intervals of no longer than 15 minutes while burning mineral oil dielectric fluid.